Speaking of Professor Schwartz, there is the following from Shai Secunda, "Dashtana - 'Ki Derekh Nashim Li''': A Study of the Babylonian Rabbinic Laws of Menstruation in Relation to Corresponding Zoroastrian Texts," (Ph.D. diss., Yeshiva University, 2007), 224, n. 532:

In Late Antiquity, beds seem to have been normally big enough for just one person. Even wealthier people probably did not purchase larger, “queen-sized” beds but instead would have created more beautiful, ornate beds without necessarily modifying their size. (Joshua Schwartz, private communication November, 2006). See Joshua Schwartz, “‘Reduce, Reuse and Recycle’: Prolegomena on Breakage and Repair in Ancient Jewish Society: Broken Beds and Chairs in Mishnah Kelim” JSIJ 5 (2006): 147-80. At the same time, a baraita found at tBer 2:14, and yQid 4:12, and a sugya at bBer 24a, discuss the laws of reciting the shema when sharing a bed [this is according to the printed editions, MS Munich 95 and apparently, the “Ashkenazi tradition” (See Or Zarua vol. 1 §133). The Eastern tradition reads, “a garment (tallit).” See MSS Florence II-I-7, Oxford Opp. Add. 23, and Paris 671] with another male, with one’s wife, or even with one’s entire family. Furthermore, a folk saying found at bSan. 7a may indicate thatcouples shared one bed (“when our love was strong we used to sleep on a bed the width of a sword. Now that our love is not strong, a bed of sixty cubits is not enough for us”). Consequently, despite the fact that beds normally did not accommodate two people, in practice, the sharing of beds or bedding may not have been an entirely uncommon, if uncomfortable, occurrence.

Within another footnote (n. 534), Secunda writes

In addition, it seems that people living in Late Antiquity generally did wear some form of nightclothes to sleep [Joshua Schwartz, private communication, November 2006].

If anyone out there knows of any other articles or are publishing any on Jewish sleep-related topics, I am interested in them.